Marine tow chain



April 1963 R. L. RATHER ETAL 3,086,491

MARINE TOW CHAIN Filed July 5, 1961 V///77u ffi G0 er/a/m IN VEN TOR-S F WW ATTORNEY United States Patent 3,086,491 MARINE TOW CHAIN Roy L. Rather'and Vilmuth P. Goerland, Houston, Tex., assignors to Commercial Engineering Corporation, Harris County, Tex., a corporation of Texas Filed .hily :5, 1961, Sen No. 122,014 ll-Claims. (Cl. 114235) This invention relates to tow chain devices, particularly of the type utilized .in towing an underwater object, such as a sounding or listening body, behind a moving vessel.

Where this type of device must carry .a harness of condu'ctor wires, it has been difficult to protect the wires from bending, stretching, and rubbing stresses both during towing, due to vibrations and flexing of the cable, and during winding and unwinding upon a drum at the stern of the vessel. Also, it has not been possible to increase the number of wires that run along the device without at the same time increasing the frontal area of the device and, therefore, its resistance to the water. The provision of fairing stabilizes "the tow chain or cable inits transit through the water, but materially complicates the problem-of winding the device "on a storage'drum. However, previous fairing arrangements mounted on tow cables have been subject to stacking up at the bottom of the cable.

Accordingly, an object of the present invention is to provide a towchain of the above type having means for protecting the supported conductor harness from the usual stretching, bendingandchafing stresses during towing operations and during winding and unwinding on .a drum.

Another objectis to :providea tow chain for submerged objects in which the individual links are provided with fairing which cooperates to constrain the conductor in an undulating or serpentine form such that the convolutions thereof are free "to flex longitudinally to minimize stresses on the conductor itself.

Another object is to provide -a tow chain having fairing within whichtheconduotor is supported in undulating or serpentine form so that longitudinal stresses are applied to relativelytfree convolutions which may flex with minimum of rubbing action against the link -and in a manner to spread bending stresses along the loops :or convolutions and thereby greatly prolong the life "of the conductor.

Another object is to provide means for substantially increasing the number "of conductor wires carried by the towing device without increasing the frontal area of the device in towing.

Theseobjects and others are attained in the herein disclosed tow fchain structure which consists'of a plurality of pivoted links, each link having a longitudinal stress bearing barwith pivotal attachments 'at the end. Parallel cheek plates project laterally from the bar .and an outwardly tapered, buoyant body is secured between the ends of these plates and forms fairing therewith. The inner face'of the buoyant body is of undulating contour so as to cooperate with suitably positioned elements between the plates for constraining the conductor harness received between the plates in undulating form which greatly minimizes stresses and wear on the conductor during loading and bending of the chain. The harness is 3,086,491 Patented Apr. 23, 1.963

of generally rectangular section for best use of the available space in the fairing and no wider than the link bars for minimum frontal area.

In the accompanying drawings which illustrate'the invention:

FIG. 1 is a schematic elevation showing the novel chain being towed behind a vessel.

FIG. 2 .is a transverse section taken substantially on line 2-2 of FIG. 3.

FIG. 3 .is an enlarged elevation showing one of the faired link structures and portions .of adjacent links, parts being broken away for clearer illustration of the underlying structure.

FIG. lshows thechain, generally designated-6, secured to a reeling drum 7 mounted on the sternof a vessel 8. At :the lower end of the tow chain is a towed .body 9 carrying suitable instruments .for the intended purpose. Carried by thetow-chain is a conductor harness-extending from body 9 to the vessel and generally designated '10.

Each link of the tow chain comprises a longitudinal stress bearing bar 12 of atrapezoidal section, deeper than its width, having aneye .13 at its upper end pivotally .receiving a U-shaped loop 14a which is suitably secured, as by welding, to the lower end of the next upper bar 12a. The loop 14 at the lower end of bar 12, likewise, is pivotally received in the eye 13a at-the top of the next lower bar 13. Projecting laterally from bar 12 flush with the inner edges thereof and, conveniently welded thereto, area pairof parallel-cheek plates .16 which, at their lower and upper ends are provided with restricted rolled or outset portions 17 and 18 for a purpose to be described. Extending between plates 16 in a line spaced somewhat outwardly from bar 12 are a pair of abutment pins 19 and 20 forming a pocket 'therebetween. Conductor harness 10 of generally rectangularsection is received between plates 16 in undulations designated 21, 22 and 23.

.Reoeived'between theouter ends of plates and forming a fairing structure therewith is an outwardly tapered member 25, preferably of buoyant material such as wood or a suitable resinoid. The inner face of member 25 is of longitudinally undulating contour including a central salient .26 and terminal salients 2.7 and 28. Central salient .26 constrains central harness convolution 21 in the pocket between pins 19 and 20, while the terminal salients form .end convolutions 22 and 2.3 of the harness, rather loosely confining .thecrests of the harness at the ends of the link between these terminal salients and the ends .of .bar 12. Outset portions 17 and 18ofthe cheek plates receive the so confined crests of the:conductors.

A pair of metal strips .30 and .31 are secured to the buoyant body 25'by means of a rivet 32 from which the strips project inwardly along the body. At the inner end of each strip there is provided a reentrant, outwardly bent, resilient ear, .as 33, which, in the assembly, is received in an aperture 34 near the outer edge of corresponding cheek plate 16. These strips and ears .form detachable securing latches maintaining the body 25 and harness =properly assembled with the remaining portions of the fairing.

In order to assemble the link with the conductor harness which, of course, is flexible, the cable is first inserted fiatwise in undulations between cheek plates 16. Body 25 is then inserted between the outer edges of the cheek plates with its undulating inner face bearing against the harness. Suflicient pressure is then applied to body to cause the cable to assume an undulating form corresponding with the contour of the inner face of the body. The central or crest convolution 21 is firmly secured in the pocket between pins 19 and 20 by means of central salient 26. However, due to the fact that voids are provided adjacent the concave sides of terminal convolutions 22 and 23, these convolutions are free to flex longitudinally to accommodate longitudinal loading applied between the links as well as bending of the chain, even the severe bending occasioned by winding the chain upon the drum. Resilient material may be lodged in these voids, if desired.

It has been found, accordingly, that the cable is substantially relieved of restricted bending stresses as well as stretching and chafing action so that durability of the cable is much increased. Nevertheless, the cable may be readily removed from and replaced within the links upon detachment and reapplication of the fairing body. The torsional resiliency of the conductor cable tends to stabilize the fairing structures in proper alignment for winding on the storage drum. The rectangular harness permits the accommodation of maximum number of conductor wires within the available fairing spaces while retaining the slim frontal aspect of the chain for less resistance to the water. Further, one or more conductors may lead out of the harness intermediate any pair of fairings as, for example, when it is desired to deploy instruments at various depths along the tow chain.

Various details are not essential and these may be modified in various respects as will occur to those skilled in the art without departing from the spirit of the invention. The exclusive use of all modifications as come within the scope of the appended claims is contemplated.

We claim:

1. In a marine tow cable;

a link structure having a longitudinal stress bearing part with pivotal attachments at its ends for adjacent links;

means forming a chamber through said structure;

a flexible conductor harness extending through said chamber;

and transversely spaced elements in said chamber bearing against longitudinally spaced portions of said harness and opposite sides thereof and constraining said portions against longitudinal displacement and said harness to an undulating path within the said structure.

2. A marine tow chain comprising a plurality of pivotally connected links each having a longitudinal stress bearing member;

a fairing member spaced transversely from said memher;

and means between said members forming an undulating path longitudinally through the link and adapted for periodic constraining engagement of a flexible conductor passing therethrough to constrain the engaged portion of said conductor against longitudinal displacement.

3. A conductor carrying link for a marine tow chain comprising a longitudinal stress bearing structure having pivotal attachments at its ends for adjacent links;

a fairing structure spaced transversely of said stressbearing structure and secured thereto;

means in the space between said structures presenting a longitudinally undulating face toward one of said structures;

and means confronting said face for confining a flexible conductor therein to a normally corresponding undulating path and engaging at least a portion of said conductor against longitudinal displacement.

4. A marine tow chain comprising a plurality of pivotally connected links;

4- each link having a longitudinal stress bearing bar with parallel plates projecting laterally therefrom;

a member detachably closing the space between said plates opposite said bar;

a flexible conductor received longitudinally between said plates;

longitudinally spaced elements between said plates hearing against one side of said conductor;

and inward salients on said closing member bearing against the opposite side of said conductor and constraining said conductor into an undulating form with a convolution between said elements and other convolutions between said elements and the ends of said walls;

there being space adjacent said last convolutions permitting flexing thereof to accommodate loading and pivoting of the chain with minimum stressing of said conductor.

5. A marine tow chain as described in claim 4 in which said closing member tapers outwardly to form fairing.

6. A marine tow chain comprising a plurality of links each comprising a longitudinal stress carrying bar with pivotaly attachments at its ends for adjacent links;

parallel walls projecting laterally from said bar;

spaced elements between said walls providing a pocket therebetween;

a flexible conductor received between said walls;

an outwardly tapered fairing member receivable between said walls opposite said bar;

said member having an undulating face opposing said conductor with longitudinally spaced central and terminal salients;

said central salient bearing against and constraining said conductor in a convolution in said pocket and said terminal salients forming other convolutions in said conductor and confining said conductor in proximity to said bar;

said last convolutions being free to flex to minimize stressing of said conductor during loading and bending of the chain;

and means securing said fairing member in position between said plates.

7. A marine tow chain comprising a plurality of pivotally connected links each having a longitudinal stress bearing bar;

parallel plates projecting laterally therefrom;

a pair of elements between said plates forming a pocket therebet-ween;

a flexible conductor received between said plates;

a fairing member received between said plates;

said member having longitudinally spaced salients hearing against said cable opposite said bar and cooperating with said elements to constrain said conductor in an undulating form with convolutions capable of flexing longitudinally during loading and bending of the chain;

and snap means for securing said fairing member in position.

8. Structure as described in claim 7 in which said snap means comprises apertures in said plates and resilient elements on said fairing member positioned to enter said apertures when said member is urged home between said p ates.

9. Structure as described in claim 8 in which said fairing member is of buoyant material and said resilient elements include strips projecting inwardly therefrom and resilient ears projecting outwardly from said strips for reception in said apertures.

10. In a marine tow cable;

a link structure having a longitudinal stress bearing par: with pivotal attachments at its ends for adjacent in s;

means forming a chamber through said structure;

a flexible conductor harness extending through said chamber;

and, an additional salient spaced longitudinally from side of said conductor and a pair of parts bearing said central salient and bearing against said one side against the convexity opposite said concavity. of said conductor to form an additional convolution 11. In a marine tow cable; therein.

a link structure having a longitudinal stress bearing 5 part with pivotal attachments at its ends for adjacent References Cited in the file of this patent i UNITED STATES PATENTS means forming a chamber through said structure;

and a central salient bearing against a concavity in one a flexible conductor harness extending through said 1,293,347 CQrwin 4, 1919 h 10 ,401,783 Vlfllcoxon June 11, 1946 a central salient bearing against a concavity in one side 2,873,013 Plodl 1959 of said conductor and a pair of parts bearing against 2,391,501 a r June 23, 1959 the convexity opposite said concavity; 2,951,111 Anderson et a1 30, 1960 

1. IN A MARINE TOW CABLE; A LINK STRUCTURE HAVING A LONGITUDINAL STRESS BEARING PART WITH PIVOTAL ATTACHMENTS AT ITS ENDS FOR ADJACENT LINKS; MEANS FORMING A CHAMBER THROUGH SAID STRUCTURE; A FLEXIBLE CONDUCTOR HARNESS EXTENDING THROUGH SAID CHAMBER; AND TRANSVERSELY SPACED ELEMENTS IN SAID CHAMBER BEARING AGAINST LONGITUDINALLY SPACED PORTIONS OF SAID HARNESS AND OPPOSITE SIDES THEREOF AND CONSTRAINING SAID PORTIONS AGAINST LONGITUDINAL DISPLACEMENT AND SAID HARNESS TO AN UNDULATING PATH WITHIN THE SAID STRUCTURE. 